The present invention relates to a method of manufacturing monomers with tertiary and/or quaternary amino groups.
Compounds of the type having formula: 
in which;
R(0) represents H or CH3;
A represents xe2x80x94Oxe2x80x94 or xe2x80x94NHxe2x80x94;
D represents a C1-C6 linear or branched alkylene chain;
R(1) and R(2), the same or different, each represent independently H or at C1-5-alkyl;
are well known from the background literature.
Important compounds in this family are N,N-dimethylamino ethyl acrylate (ADAME) and N,N-dimethylamino ethyl methacrylate (MADAME): 
where Rxe2x95x90H or CH3.
A very large number of publications and patents describe the manufacture of aqueous solutions of quaternary ammonium salts ((M)ADAMQUAT) based on ADAME and MADAME respectively, the most representative of these salts being expressed by the formula: 
where Rxe2x95x90H or xe2x80x94CH3 and R(3)xe2x95x90xe2x80x94CH3 or benzyl ((M)ADAMQUAT MC or (M)ADAMQUAT BZ depending on whether R(3) represents CH3 or benzyl).
This reaction is a quaternisation, in the presence of water, of the initial compound with a quaternising agent R(3)xe2x80x94Cl.
The resultant aqueous solutions of quaternary salts are used in particular to prepare polymers intended for use as cationic flocculants in the treatment of water.
During research and development work on these polymers, the applicant company has discovered that compounds of formula (I): 
in which:
R1 represents H or xe2x80x94CH3;
R2 represents one of xe2x80x94CH3, xe2x80x94C2H5, xe2x80x94C3H7 and xe2x80x94C4H9;
the two R3 are the same or different and each represents one of xe2x80x94CH3, xe2x80x94C2H5, xe2x80x94C3H7, xe2x80x94C4H9 and xe2x80x94CH2C6H5; and
the two Xxe2x8ax96 are the same or different and each represents Clxe2x8ax96 or Brxe2x8ax96,
known by CZ-A-250 962, and in particular those in which R2xe2x95x90CH3, R3xe2x95x90CH3 or benzyl and where Xxe2x8ax96xe2x95x90Clxe2x8ax96 (which are denoted here by the abbreviation (M)ADAMQUAT 2MC or 2BZ depending on whether R3 represents CH3 or benzyl), enable aqueous dispersions to be prepared, either saline or without salt, thereby offering a solution to technical problems facing the person skilled in the art, these dispersions forming the subject matter of three French patent applications filed this day in the name of the applicant company.
Accordingly, the underlying objective of the present invention is to propose a method of manufacturing compounds having formula (I) as defined above, characterised in that at least one quaternising agent of formula (II):
R3xe2x80x94Xxe2x8ax96xe2x80x83xe2x80x83(II)
in which R3 and Xxe2x8ax96 are as defined above, is introduced into a solution, in an organic solvent or in a mixture of organic solvents, of a compound having formula (III): 
in which R1 and R2 are as defined above, at a temperature of 35 to 80xc2x0 C., then the reaction is allowed to continue at said temperature, until compound (III) has disappeared completely or substantially completely, after which water is added and then an aqueous solution of compound (I) is separated and the water removed as necessary.
An example of a compound (I) is a compound having formula (Ia): 
which may be designated by the abbreviation S-ADAMQUAT 2BZ.
Advantageously, the reaction is conducted with a molar ratio of quaternising agent (II)/compound (III) in a range of between 1.8 and 3.
The organic solvent used is chloroform, dichloromethane or dichloroethane, for example. A mixture of such solvents may also be used.
The reaction is not generally conducted under pressure unless the quaternising agent (II) is in the gaseous state.
The quaternising agent (II) is introduced into the solution of compound (III), generally over a period of 0.5 to 2 hours, and, once all the quaternising agent *has been introduced, the reaction of compounds (II) and (III) is conducted, generally over a period of 10 to 40 hours.
After separating the aqueous solution of compound (I), it is preferable to remove all traces of organic solvent from the resultant aqueous solution by stripping in air at a reduced pressure.
Said method results in an aqueous solution with a concentration of compound (I) which is preferably between 65 and 75% by weight.
According to one specific feature of the above method, it is conducted in the presence of at least one stabiliser selected in particular from hydroquinone, hydroquinone methyl ether and 3,5-ditert.-butyl-4-hydroxytoluene and mixtures of these stabilisers, the content of stabilising agent(s) being in particular 400 to 2000 ppm relative to the aqueous solution of the final compound (I).
Compound (III) may be prepared by causing a compound of formula (IV): 
in which R2 is as defined above, to react with (meth)acrylic anhydride in the presence of triethylamine, with, a molar ratio of (meth)acrylic anhydride/compound (IV) of 0.5 to 2, at a temperature of 20 to 100xc2x0 C., in particular 30 to 60xc2x0 C., for a period of 2 to 10 hours in the presence of at least one stabiliser such as phenothiazine, hydroquinone methyl ether, 3,5-ditert.-butyl-4-hydroxytoluene and hydroquinone and mixtures of these stabilisers in a ratio of 200 to 3000 ppm relative to the charge.
In the reaction with (meth)acrylic anhydride, the triethylamine acts as a catalyst for the reaction, and traps the resultant (meth)acrylic acid in the salt form. It is generally used in an equivalent molar ratio of 1 to 2 relative to the (meth,)acrylic anhydride.
Another objective of the present invention is to propose homopolymers or copolymers containing units of at least one monomer of formula (I) obtained by the method as defined above.
The copolymers based on the monomers (I) incorporating the monomer (Ia) may be water-soluble or hydrophobic polymers in the form of an aqueous dispersion, latex, aqueous solution, inverse emulsion or powder. They are prepared by radical copolymerisation using various synthesis methods such as polymerisation in dispersion, solution, direct emulsion, inverse emulsion and inverse suspension.
The examples below, given by way of illustration only, provide a clearer understanding of the invention. In these examples, the specified proportions and percentages are by weight, unless stated to the contrary.
The following abbreviations are used in these examples:
S-ADAME: compound of formula: 
EMHQ: hydroquinone methyl ether.